Properties of advanced coupled-cluster Green's function

ABSTRACT

We present an extension of the analysis previously applied to the retarded part of the coupled cluster (CC) Green's function to its advanced part. In analogy to our earlier studies for the retarded part, we demonstrate that the advanced CC Green's function is expressed in terms of connected diagrams only, which is a direct consequence of algebraic form of equations satisfied by CC amplitudes. We also demonstrate that ω-derivatives of the advanced CC Green's function can be calculated analytically and can be expressed in terms of connected diagrams only. We analyse the structure of connected diagrams and the role of intermediate operators which satisfy electron affinity equation-of-motion CC-type conditions.

KEYWORDS:

• Advanced Green's function
• coupled cluster
• connected diagrams
• ω-derivatives
• self-energy

Acknowledgment

This work has been performed using the Molecular Science Computing Facility (MSCF) in the Environmental Molecular Sciences Laboratory (EMSL) at the Pacific Northwest National Laboratory (PNNL). EMSL is funded by the Office of Biological and Environmental Research in the U.S. Department of Energy. PNNL is operated for the U.S. Department of Energy by the Battelle Memorial Institute under Contract DE-AC06-76RLO-1830. B. Peng acknowledges the Linus Pauling Postdoctoral Fellowship from PNNL. K. Kowalski acknowledges support from the Extreme Scale Computing Initiative, a Laboratory Directed Research and Development Program at Pacific Northwest National Laboratory.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

U.S. Department of Energy; Extreme Scale Computing Initiative, a Laboratory Directed Research and Development Program at Pacific Northwest National Laboratory.